Structural Pest Control Applicator Practice Exam

When a pesticide evaporates and moves off target, this is referred to as what?

1. Spray drift.

2. Pesticide runoff.

3. Vapor drift.

4. Soil leaching.

The correct answer is: Vapor drift.

The movement of a pesticide after it evaporates from its original surface and disperses into the air is called vapor drift. This phenomenon occurs when the active ingredients in the pesticide are transformed into a gaseous state and can travel through the air, impacting areas that were not intended to be treated. Vapor drift can pose risks not just to surrounding vegetation and non-target organisms but also to nearby human populations. In contrast, spray drift involves the airborne movement of liquid pesticide droplets during application, often influenced by factors like wind speed and droplet size. Pesticide runoff refers to the movement of pesticides in water, typically during rainfall or irrigation, leading to contamination of nearby water bodies. Soil leaching occurs when pesticide residues dissolve in water and move down through the soil profile, potentially reaching groundwater. Understanding the distinct nature of vapor drift as a result of evaporation is crucial for effective pest control and minimizing environmental impact.